English

fkcompute: an efficient $F_K$ invariant calculator

Geometric Topology 2026-07-13 v1 Mathematical Software Quantum Algebra

Abstract

We introduce fkcompute, an open-source package for computing the Gukov--Manolescu invariant of links from a braid presentation. fkcompute implements Park's inverted state sum through a three-phase pipeline. First, a search is performed for a suitable braid presentation and for an additional inversion data on the braid. Then, the state space of the inverted sum is encoded as a polytope, bounded by the associated linear constraint system. Finally, the invariant is constructed by multiplication of R-matrices associated to the states. Benchmarks show that prime knots up to 12 crossings, and prime links up to 10 crossings and of at most 3 components, are comfortably within reach. As a result, fkcompute is used to compile the first public database of the Gukov--Manolescu invariant. The package is available as a Python library, a command-line tool, and a Mathematica paclet.

Cite

@article{arxiv.2607.12155,
  title  = {fkcompute: an efficient $F_K$ invariant calculator},
  author = {Paul Orland and Davide Passaro and Lara San Martín Suárez and Toby Saunders-A'Court and Josef Svoboda},
  journal= {arXiv preprint arXiv:2607.12155},
  year   = {2026}
}

Comments

17 pages, 1 figure, 1 table, GitHub repository: github.com/caltech-quantum-topology/fkcompute, database: topology.fyi